Single Pipe Primary Secondary & Tee Placement

Subcool1974

I have a contractor who re-piped a residential boiler system 2 weeks ago.  The system contains an indirect water heater, a pool heater, and two zones of radiant floor heating.  The original piping was...shall we say..."creative"...and flat out wrong.  There were no closely spaced tees on the project at all and the boiler ran nearly constantly.  All heating zones essentially pulled their heat from the indirect water heater...and the aquastat on the indirect was the only device telling the boiler to fire. 

The system was re-piped as a single pipe primary secondary layout with the indirect piped as a heating zone...and all zone supply & return tees being closely spaced.  Being single pipe, the return tee from zone 1 is followed by the supply tee for zone 2 and so on.  Here's the concern...those two tees are also closely spaced.  Essentially, I'm looking at a stack of ProPress tees.  Is there a minimum distance you should maintain between zones?  What effect would having the tees too closely spaced have on the system?

Ironman

Tees

It should have no effect as long as there are not any turns between the sets of tees or there's not an over-pumped zone causing reverse flow between its Tees.What would concern me is, if I understand your description correctly, that your secondary's are piped in series off the primary. That means that each loop will get cooler supply water as you get father away from the boiler supply. This is alright if the system was designed for it, but your post leads me to think otherwise.